The complete work was to include 10 vols., but only 4 were published
First monograph (v. 1-2) in 3 parts; second monograph (v. 3-4) in 5 parts
vol. I. pt. I. Essay on classification. pt.II. North American Testudinata. 1857.- vol. II. pt. III. Embryology of the turtle. 1857.- vol. III. pt. I. Acalephs in general. pt. II. Ctenophoroe. 1860.- vol. IV. pt. III. Discophoroe. pt. Iv. Hydroidoe. pt. V. Homologies of the Radiata